In a complete succession obtained from southeast of Birjand, in the Eastern part of Iran, the open marine sediments have been deposited without any disconformity from Paleogene to early Neogene systems. We conducted the biostratigraphic investigations within this sedimentary succession according to calcareous nannofossils from the Roobiat Village section. Based on the calcareous nannofossil species index, we have detected the NP16 to NN3 zones and subzones which are comparable with the Martini biozonation pattern. Thus, we could suggest a middle Eocene (Bartonian) to early Miocene (Burdigalian) age for this section. Since the studied section contains a complete sedimentary sequence from Paleogene to Neogene systems, as a comparisonal section for the correlation between bio-horizons from western parts of the Tethys basin and its eastern parts, it is recommended.
Biostratigraphy
1. Aghanabati, A. (2006), Geology of Iran, 573 pp. Geological survey of Iran, Tehran
2. Agnini, C., E. Fornaciari, et al. (2014), Biozonation and biochronology of Paleogene calcareous nannofossils from low and middle latitudes, Newsletters on Stratigraphy, 47, No. 2, 131-181
3. Backman, J., I. Raffi, et al. (2012), Biozonation and biochronogy of Miocene through Pleistocene calcareous nannofossils from low and middle latitudes, Newsletters on Stratigraphy, 45, 221-244
4. Berberian, M., G. C. P. King (1981), Towards a paleogeography and tectonic evolution of Iran, Canadian Journal of Earth Sciences, 18, 210-265
5. Bown, P. R. (1998), Calcareous Nannofossils Biostratigraphy, 315 pp. Kluwer Academic Publishers, Dordrecht
6. Bown, P. R., J. R. Young (1998), Techniques, Calcareous Nannofossil Biostratigraphy, P. R. Bown Ed.) p. 16-28, Kluwer Academic Publishers, Dordrecht
7. Bown, P. R., D. T. Jones (2012), Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334), Journal of Nannoplankton Research, 32, No. 2, 3-51
8. Bukry, D. (1973), Low-latitude coccolith biostratigraphic zonation, Initial Reports of the Deep Sea Drilling Project, 15, 685-703
9. Bukry, D. (1978), Biostratigraphy of Cenozoic marine sediments by calcareous nannofossils, Micropaleontology, 24, 44-60
10. Fazli, L., S. Senemari (2018), Calcareous nannofossil biostratigraphy of the Eocene of the Zagros Basin in Iran, Neues Jahrbuch f¨ur Geologie und Pal¨aontologie, Abhandlungen, 287, No. 2, 143-151
11. Hadavi, F., M. Notghi Moghaddam, L. Khodadadi (2016), Biostratigraphy and paleoecology of Cretaceous rocks based on calcareous nannofossil in Sarayan section, East Iran, Iranian Journal of Earth Sciences, 8, No. 1, 52-68
12. Jalili, F., M. Notghi Moghaddam, F. Hadavi (2020), Investigation of the Silak Section Filyschoid deposits based on calcareous nannofossils and comparison with Shushud and Sarayan sections (East Lut Block), Kharazmi Journal of Earth Sciences, 5, No. 2, 159-174
13. Lohmann, H. (1909), Die Geh¨ause und Gallenblasen der Appendikularien und ihre Bedeutung fur die Erforschung des Lebens im Meer, Verh. Dtsch. Zool. Ges., 19, 200-233
14. Martini, M. (1971), Standard Tertiary and Quaternary Calcareous Nannoplankton Zonation, Proc. of the 2nd Planktonic Conference Roma, 2, 739-785
15. Okada, H., D. Bukry (1980), Supplementary modification and introduction of code numbers to the lowlatitude coccolith biostratigraphic zonation, Marine Micropaleontology, 5, 321-325
16. Parandavar, M., F. Hadavi (2019), Identification of the Oligocene-Miocene boundary in the Central Iran Basin (Qom Formation): Calcareous nannofossil evidences, Geological Quarterly, 62, No. 2, 215-229
17. Perch-Nielsen, K. (1985), Cenozoic Calcareous Nannofossils, Plankton Stratigraphy, H. M. Bolli, J. B. Sanders & K. Perch-Nielsen (Eds.) p. 427-554, Cambridge University Press, Cambridge
18. Scotese, C. R. (2013), Paleogeography, Encyclopaedia Britannica publisher, Edinburgh. (https://www.britannica.com/science/paleogeography)
19. Tirrul, R., I. K. Bell, et al. (1983), The Sistan suture zone of eastern Iran, Geological Society of American, Bulletin, 94, 134-150, (in Russian
